Sanwa Supply is selling a wireless mouse, 400-MA052, for ¥2,980. It runs without a battery or battery charging. It is powered wirelessly from the accompanying mouse pad.
Once you connect the mouse pad to a USB port, it starts producing a magnetic field, powering the wireless mouse’s circuit.
Wireless mouse: W67 x H37 x L105mm, 72g
Mouse pad: W105 x H215 x L15mm, 140g / Cable length: 1.4m